But on combining a cubic inch of pure nitrous oxide with some of the same water, which had been received under mercury in a separate vessel, nearly ¹/₂₂ remained. Consequently we may conclude, that 5,1 of a gas unabsorbable by water, was produced in the combustion.
This gas extinguished flame, gave no diminution with oxygene, and the slightest possible with nitrous gas. When an electric spark was passed through it, mingled with oxygene; no inflammation, or perceptible diminution took place.[84] We may consequently conclude that it was nitrogene, mingled with a minute portion of common air, expelled from the water.
The charcoal was diminished in bulk to one half nearly, but the loss of weight could not be ascertained, as its pores were filled with mercury.
Now 5 cubic inches of nitrous oxide were absorbed by the water, consequently 5 were decompounded by the charcoal; and these produced 5,1 cubic inches of nitrogene; and by giving their oxygene to the charcoal, apparently 2,4 of carbonic acid.
But 5 cubic inches of nitrous oxide weigh 2,5 grains, and 5,1 cubic inches of nitrogene 1,55; then 2,5-1,55 =,95.
So that reasoning from the relative specific gravities of nitrogene and nitrous oxide, 2,5 grains of the last are composed of 1,55 nitrogene, and,95 oxygene.
But from many experiments made on the specific gravity of carbonic acid, in August, 1799, I concluded that 100 cubic inches of it weighed 47,5 grains, thermometer being 60,1°, and barometer 29,5. Consequently, making the necessary corrections, 2,4 cubic inches of it weigh 1,14 grains; and on Lavoisier’s and Guyton’s[85] estimation of its composition, these 1,13 grains contain 8,2 of oxygene.
So that, drawing conclusions from the quantity of carbonic acid formed in this experiment, 2,5 grains of nitrous oxide will be composed of,82 oxygene, and 1,68 nitrogene.
The difference between these estimations is considerable, and yet not more than might have been expected, if we consider the probable sources of error in the experiment.
1. It is likely that variable minute quantities of hydrogene remain combined with charcoal, even after it has been long exposed to a red heat.